Daikin Outdoor Unit Ceiling Mounted Cassette Type Heat Pump RX09RMVJU9A

Warning: This procedure requires trained personnel with PPE!

If power is not turned off, stop the procedure and turn off the power

Inverter analyzer installed instead of a compressor?

Warning: Ensure the charged voltage of the built-in smoothing electrolytic capacitor drops to 10 VDC or below before proceeding

Terminals removed from the compressor and connected to the inverter analyzer?

Warning: Do not let the terminals (U,V,W) touch each other. High voltage is applied.

Power transistor test operation activated from the outdoor unit?

Note: Power transistor test operation can be activated only once after turning on the power supply. If reactivation is needed, turn the power supply off and then on again.

Check No.16: Make sure that the voltage is within 320 VDC.

Set operation off and power off. Disconnect the connector S70 or S71.

Control voltage between the pins 4 - 3

Rotation command voltage between the pins 4 - 2

Keep operation off and power off. Connect the connector S70 or S71.

4 rotation pulses (0 ~ 15 VDC) at the pins 4 - 1 when the fan motor is rotated 1 turn by hand.

If NG in step 2 -> Defective PCB -> Replace the outdoor unit PCB (main PCB).

Warning: Ensure the voltage between (+) and (–) of the power module is approximately 0 V before proceeding.

Disconnect the compressor harness connector from the outdoor unit PCB. Press the protrusion on the connector to disengage.

Connector disengaged successfully?

Measure resistance between the terminals of the power module and the terminals of the compressor with a multimeter.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module check

Check the connection of connector

Check motor power supply voltage output (pins 5 ~ 8)

Check motor control voltage (pins 5 ~ 4)

Check rotation command voltage output (pins 5 ~ 3)

Check rotation pulse input (pins 5 - 2)

Sign off on the connector output check

Measure the power supply waveform between No. 1 and No. 2 on the terminal block

Check if the power supply waveform is a sine wave (Fig.1)

Check if there is waveform disturbance near the zero-cross (sections circled in Fig.2)

Sign off on the power supply waveforms check